Part VI
Verification
E. Algorithm and software checks · Portal frame sway
Two columns four meters tall stand six meters apart. A beam joins their tops, and both bases are fixed. A lateral force of 3.0 N acts at the top of the right column. How far does the frame sway?
The reference does not calculate sway by hand. The expected value is the solver answer stored when the case was made. The case tests repeatability of assembly and solution for several elements. It does not compare the solution with an independent answer.
This page preserves a recorded benchmark and its expected values. The dated run below is not a new run of the current product.
A slope-deflection solution would give the sway in closed form. Until that solution is added, this case shows only that the solve repeats.
1.Inputs.
Illustrative values, taken from no standard and chosen so the arithmetic can be followed by hand. Most do not describe a real pipe; read them in any consistent set of units.
| Quantity | Symbol | Value |
|---|---|---|
| Node 0 (left base) | — | (0.0, 0.0, 0.0) m |
| Node 1 (left top) | — | (0.0, 4.0, 0.0) m |
| Node 2 (right top) | — | (6.0, 4.0, 0.0) m |
| Node 3 (right base) | — | (6.0, 0.0, 0.0) m |
| Elastic modulus | E | 1800.0 Pa |
| Shear modulus | G | 700.0 Pa |
| Area | A | 2.5 m2 |
| Second moment about y | Iy | 2.0 m4 |
| Second moment about z | Iz | 2.0 m4 |
| Torsion constant | J | 1.0 m4 |
| Lateral force at node 2, global X | F | 3.0 N |
2.Method.
No hand calculation of the sway is given. The reference records the frame, its supports and its load. The expected top-right sway is taken from the solver’s frame assembly and dense solution of the restrained system.
3.Results.
| Quantity | Expected |
|---|---|
| Top-right sway in X | The solver’s stored result; no hand value |
The case record describes these checks:
- The solver assembles the three members and solves the restrained system.
- The solved sway equals the stored value, which the solver itself produced.
- The solved sway is a finite number.
What it shows. Checks that the solved value repeats a stored value. It is not an independent check.
Path exercised. Frame assembly and solve, compared with a stored result. The comparison establishes repeatability only.
Agreement. The solved sway must repeat the stored value within an absolute difference of 1.0 × 10−9 m. This shows repeatability only, not agreement with an independent answer. Long values are shown here to seven significant figures; the tests compare the full values in the record.
4.Recorded command.
This command belongs to the linked case record and its recorded execution path. This website update did not rerun it. A historical command or result does not establish current product support.
cd projects/chirality-piping cargo test --manifest-path validation/benchmarks/mechanics/Cargo.toml portal_frame_fixture_solves_repeatably
Hand calculation:
validation/hand_calcs/mechanics/portal_frame_sway.md.
Test record, with the recorded run of 2026-07-10:
mech-portal-sway-original.md.